Polymerization of olefins



POLYMERIZATION or OLEFINS Jack W. Ralls, Berkeley, Caliii, assignor toCalifornia Research Corporation, San Francisco, Califi; a corporation ofDelaware No Drawing. Filed Dec. 28, 1956, Ser. No. 631,025 1 3 Claims.01. 260- 935 Thisin'vention relates to a process for polymerizingrelatively low molecular weight olefins to produce solid crystallineolefin polymers and to 'a novel catalyst for such polymerizations.

It is an object of this invention to provide a process for polymerizinglower olefins characterized by high COD: versions and high yields ofsolid crystalline polymers.

It is a further object of the invention to provide a new polymerizationcatalyst capable'of catalyzing the polymerization of relativelylowmolecular weight olefinsv to produce predominantly crystalline olefinpolymers. M I Pursuant to the invention, l-olefins containing from 2 to6 carbon atoms per molecule and having no chain branching closer to theolefin double bond than the 3 carbon atomare polymerized by contactingthe olefinic material with a catalyst consisting essentially of adispersion of AlTi Cl and an alkali aluminum hydride in a rionpolarliquid. The process is carried out at a Patented Apr. 18, 1961 2 VEXAMPLE 2 ice l' 'olymeiizatic nibl. propylene pursuant to the processof the invention is illustrated in the following exampe: A 360milliliter rocking'bornb was flushed with nitrogen to remove air andwater vapor and charged with 100 m1. of mixed hexanes, 1.0 gram of A-lTiCl and 0.5 gram of LiAll-L, powder. The bomb was closed and flushedthree times with nitrogen at 200 gsig. 'Nitrogen was bled frorinthe bombto atmospheric pressure and 37 grams of Phillips 99% propylene wasintroduced. The

bomb was sealed and heated with shaking for one hour. 1

During the last half of this period, the temperature was in therange7l1to 87 C. and the pressure was in the "range 180 to 1.30 p.s.i.g.The shaking was interrupted-and an additional 15 grams ofpropylene wasin- 't'rodu'ced into the bomb, which was then heated and shaken for 2 /2hours. The temperature and pressure during this period were 92-'97 c.and 130-215 'p.s.i.g.

, was heated on a steam plate for one hour, during which moderatelyelevated pressure and at a relatively low teinperature usually belowabout 150 C.

The invention is more particularly described in the following examplesand tabulated data summarizing results obtained pursuant to the processof the invention as operating "conditions, catalyst composition, andolefin feeds are varied.

EXAMPLE 1 An illustrative preparation of the aluminum titanium chloridecomponentiof the catalyst ma be carried out in thefollowing manner-: A250 ml. stirred reactor was flushed with nitrogen to removeelementaloxygen. 100

ml. of mixe li hexanes, 18.98 (0.1 mol) grams of titanium tetrachloride,'and- 1.35 (0.05 gramatornygrams of aluthe volume reduced to 1 00 nu.and 100 ml. of '12 N hydrochloric acid were then added to thehe'akerfwhieh was heated on a steam plate for'one hour. At the end ofthis period the contents of the beaker were filtered and the filtercakewas washedwith water, The filter cake was then groundto a powder in aWaring Blendorjanld resuspended in 300 ml. of water, 100 ml. tif 12 Nhydrochloric acid and 100ml; o .Zrrmao ,h s1 ni was h t d rs a andfiltered. The filter cake was washed with water, with dilute ammonia,and againwith water. The filter cake was then extracted with diethylether to remove After the extraction 28 grams of amorphous polymer. dry,solid crystallinepolymer remain. The ether wash- ,ings were diluted withmethanol and water. The amorphous polymer contained in the etherseparated out as a gummy mass which was separated, dried, and weighed.

The weight of theamorphous polymer was 11.62 grams.

minum powder were then' introduced into the reactor.

hydrocarbon filtrate and asolid filter cake. The filter 60 cake waswashedwith mixed hexanes, dried in anitrogen atmosphere, and bottled,while still in the nitrogen atmosphere. ,'19. 19,gr ams of solidproductowere obtained. The

s d 'wa's'a recldish-p'u'rpl'e amorphous material. There was no.evidence that it contained more'than traces of flnreactedaluminum or anyunreacted titanium tetrachloride. Analysis of the solid indicates it'tohave a com- .Ihereactorwas then-closed and twice fiushed'with "nitrof'gen fat 2(l0jp.s.i.g. 'The'nitrogen' was then-vented from The reactorwas then' sea-led and T pesitioncorresponding to the empirical "formula'AlTi 'Cl This 'solidalonehas no capacity to catalyze polymerization, ofolefins' but when it is dispersed in a nonpolar liquid together "with analkali aluminum hydrode,the .resultant dispersion is ahighly effectivepolymerization catalystf y .:.j

- hours fftfQ get almost complete solution. -was transferred to a glovedbox and all the air and water EXAMPLE 3 suspension of 2.0 grams ofpowdered LiAlH in 200 ml. of dry ethyl ether was heated under reflux forsix- The solution vapor displaced by dry nitrogen. The LiAlI-L;suspension was treated with 2.33 grams of powdered anhydrous aluminumchloiide'add'ed in portions. The suspension was filteredyafter-one-hourto remove. the LiCl' and the undi'ssolved residue from the LiAlHsolution. The color less ether solution. of AlH ;Was treated with 1.0gram of finely divided sodium hydride. After a few minutes,

the suspensionbecame turbid and a light grey colt'iredsolid appeared asacoating on" the surface of the sodium After thr'e'exhours, the solidwas collected by hydride. filtration. and washed with ether. The weightat the solid was; 1.11 2; grams.- The yield of NaAlH, mixed with NaH.was 0.24 gram. .;.A separate experiment showed that a mixture -of,-NaH- and A1Ti Cl did not catalyze the p lyrne when of ethylene at 124c. 'and 3l75 p.s.i.g.

A 360 milliliter rocking bomb was flushed with nitrogen and'chargedwithmilliliters of mixed hexane, 1.0 i gram OfJAlTiCl and 1.12 gramsofmixedNaA1H N-aH The-bomb was capped,

preparedies describedabove.

' and connected. The bomb andlin'esjwere'fiushecl three 300 fill, atwater 'to.:8.0 grams of propyl'ehei"? 11 times at 200 p.s.i.g. withnitrogen. After a pressure check and venting of the nitrogen, 72 gramsof Phillips 99% propylene was added. The bomb was shaken and heated at90118 C. and 320-535 p. s.i.g. toreighteen hours. The bomb was vented torelease excess propylene, faud the system flushed with nitrogen The bombwas opened and its contents transferred intoZOOmLof isopropyl alcohol.-After heating on a steam plate for two hours, water and hydrochloricacid were added. An oil phase separated out. After heating the mixturefor three hours, the oil was separated in a separatory funnel. The oilwas washed with water, diluteammonia, and water. The product was a greycolored, turbid, rather mobile oil weighing 17.6 grams. 7

V A series of runs in which the proportions of lithium aluminum hydrideand AlTi Cl were varied while reaction conditions were otherwisemaintained substantially as shown in Example 2, are summarized in thefollowing Table I. Thevyield figures inTable I and in certain of TableII EFFECT or PRESSURE Yield, g. Average Run Pressure. Ratio p.s.i.g.Crystal- 7 Amorline phous- The runs tabulated in the following Table IIIillustrate the eiiect of temperature on the process of the invention.Conditions in the .runs correspond to those employed in theruns of TableII, exceptior the maximum temperature employed. 4

the other tables below report yields of both crystalline T bl [1 andamorphous polymer. Both types of polymer are EFFECT OF TEMPERATURE-solid, but the crystalline polymer is characterized by a sharp meltlngp01nt, while the amorphous polymer has Maximum .Pmduct Intrinsic nosharp melting point butsrmply softens as the temper- Run Tgmo, MeltingPolymer Film Char- Viscosity, ature is raised, much as glass does. EdL/g' '12s 150-163 Quitcbrittle I Table I V 140 158-101 Very hriitle i.4.85 H V ill t EFFECT OF VARYING PROPORTIONS 0F LIAIHKAND 12th? ii riiil i 5. 8 AlTlzClg 96 160-163 Tough. flexible 2.85

' V I Intctralinat120C. CaHe LiAlH armors, Yield"; j 1 r 1 '3 gf Crvstabm Ram From the tabulated'data and'rsimilarrruns, it is conline phonecluded that polymerizationoccurs readily at moderately elevatedtemperatures desirably below. 150? C. and, preff g3 erably; in the rangeabout 70 'toyl40" C. 57 m v 33 5 5; r In the following Table IV, dataare presented from 70 .0 0 -5 1 0 runs in which the lithium aluminumhydride and AlTizclg were dispersed in several nonpolar liquids. .I

Table IV v EFFECT or MEDIUM 0.5 g. Lmlrn, 1.0 g. AiTnCIS, 380-490p.s.l.g., 90-105" 0.1

Q 1 'Yisid f 1 A 1 m -Run Propy: Solvent, ml. Melting No. lene, g. VRatio Range -Fllm Crystalline Amort phous r 57 Mixed Hcxnnes.. 33 i 15.9,2.1/1 161-3 'Tougha 94 (yclohcxanc 51.7 14.2 3. (iii ,160-3 Do. 87 DQ..lill'l 42.2 8.5 5/1 1624 Do. 112 hire on. as 10.2 6.4/1 158-l68 Do.

From the runs summarized in the above table and from observations inother runs, the conclusion is reached that the mol ratio of the hydrideto the aluminum titanium chloride, is desirably held in theIrange .5:.lto 10:1. Preferably, approximately equimola'r quantities of the hydrideand the aluminum titanium chloride are employedin preparing thedispersion which constitutes the catalyst. i e

' The runs summarized in the following Table II illustrate the resultsobtained at several pressures using nitrogen as the gaseousdiluent to.maintain the desirednpressures. The catalyst used in the tabulatedrunsiwas 0.5 gram of lithium aluminum hydride-and -1 .0 gram of AlTi Cldispersed in mixed hexanes; The'tempcrature in the runs was 910:to' 104C; andthe charge was 68 morethan 6 carbon atoms per molecule may be.em-.

ployedfl j p jInthe following'TablezV, data'are presented illustrateing' the character .of the polymeric. products. obtained when certainolefinic hydrocarbons are polymerized put-1 suant to the processof'the'invention. Conditions employed in the'runsshownin Table Vcorrespond tothe conditionsemployed in the runs set forth in Table'IY;v.1.

Table V CONDITIONS AS IN TABLE IV-MIXED HEXANES Product, g. Melting RunOlefin Weight, Ratio Range, Film No. g. O.

Crystalline Amorphous 1 H; 50 17 131-142 Strong. 2 l-butene 77 35.2 32.11.1/1 101-2 Soft, shows stretch orientation. 1,3-butadiene 76 50.3orange, rubbery solid l-octene 50 None l-octene all recovered Styrene 5050 gummy solid 3-methyl-l-butene 74 11.4 1.0 11/1 227-232 Will not moldat 240 0. l-hexene 61 47 grey, ru obery solid 2-methyl-1-butene 85 liiuid The tabulated runs and exploratory runs adapted to I claim:

determine the range of effectiveness of the catalyst to polymerizeolefins indicate that the catalyst is effective to produce solidpolymers from l-olefins containing from 2 to 6 carbon atoms per moleculeand having no chain branching closer to an olefinic double bond than the3 carbon atom. For example, no highpolymer is produced from2-methylbutene-1, While 3-methylbutene-1 yields a solid crystallinepolymer, as indicated in the above Table V. Diolefins containing 4 to 6carbon atoms per molecule, having at least one of the double bonds in al-position in the chain, and having no branching of chain closer to adouble bond in the l-position then the 3 carbon atom relative to thatbond, yield crystalline polymers pursuant to the process of theinvention.

In the following Table VI, the properties of the illustrative copolymersproduced by the process of, the invention are shown. Conditions in theruns correspond to conditions in the runs employed in Table IV.

1. A polymerization catalyst consisting essentially of finic double bondthan the 3 carbon atom and styrene,

which comprises contacting at least one of said selected materials witha catalyst consisting essentially of a dis persion of AlTi Cl and analkali metal aluminum hydride in a nonpolar liquid at a temperaturebelow about 3. The process as defined in claim 2, wherein the selectedmaterial is contacted with the catalyst at a temperature in the range 70to 140 C. under a superatmospheric pressure in the range 100 to 1000p.s.i.g.

Table VI COPOLYMERS Propor- Product g. Melting Run N o. (Jo-monomerstion by Ratio Range, Film Weight C. in Feed Crystalline Amorphous 1 i 1Heterogeneous, flexible, 1 4 42.3 13.8 3/1 150-170 bending, givesfibrous 's ri ii ifi' trth r v 1 o,exiesec oren j 2 31.8 34.0 0.9 1 101130 Mon V a 10.5 4.7 2.2 1 159460. White, opaque, brittle.

'10 Moderately fleirlblc fllm' 4 {Ethylene "e O 1 130 152 fibrousstructure.

Cracked Wax Olefins 10 5 v 1 124 142-192 Dlfliculttomold.

Both the crystalline and amorphous polymers shown in the above Table VIare true copolymers. The variety During numerous polymerization runs,the concentration of the AlTi cl -alkali aluminumhydride catalyst in Ithe non-polar liquid was varied over considerable range.

Catalyst concentrations ranging from about 0.2% to 10% by weight in thenon-polar liquids are efiective.

Yields of the order of 50 parts by weight of crystalline.

polymer per part by weightof catalyst are readily obtained pursuanttothe process of the invention.

References Cited in the file of this patent UNITED STATES PATENTS2,721,189 Anderson et al Oct. 18, 1955 2,839,518 Brebner et'al. June17,1958 2,886,561 Reynolds et al. May 12, 1959 2,899,414 Mertes Aug. 11,1959 2,905,645 Anderson et al'. Sept. 22, 1959 FOREIGN PATENTS 874,215Germany v Apr. 20, 1953 538,782 Belgium Dec. 6, 1955 OTHER REFERENCESRalf et al.: Polyethylene, pages 72,81, clnterscience finely dividedA1Ti Cl and a finely divided alkali metal- Rutf-et alzizietschriftfiiranorg. chem; (February 1 v 23,1923), pages 81-95. I

2. A PROCESS FOR POLYMERIZING SELECTED FROM THE GROUP CONSISTING OF1-OLEFINS CONTAINING 2 TO 6 CARBON ATOMS AND HAVING NO CHAIN BRANCHINGCLOSER TO THE OLEFINIC DOUBLE BOND THAN THE 3 CARBON ATOM AND STYRENE,WHICH COMPRISES CONTACTING AT LEAST ONE OF SAID SELECTED MATERIALS WITHA CATLYST CONSISTING ESSENTIALLY OF A DISPERSION OF ALT2CL8 AND ANALKALI METAL ALUMINUM HYDRIDE IN A NONPOLAR LIQUID AT A TEMPERATUREBELOW ABOUT 150*C.